Fixing broken fairings with Plastex

As noted here, I’ve been doing a little work on a 1990 Kawasaki 250. The first project involved fixing the cracked fairings. Now I am not going for perfection here; this fix is simply to get them functional again; not to restore the bike to the original condition. That would (at the least) require some body work and repainting. I am just going to fix the fairings using a product that allows a solid repair with little work or cost that will leave the bike looking decent. I’ve used Plastex in the past on a personal project and found it worked very very well and so I thought I would demonstrate it’s use for this project. Plastex is a product of Canada but is available from several US resellers. I picked some up from J&P Cycles for this project.

Here are the fairings prior to repair. The belly cowl was broken in half and the main fairing had cracks on both sides; one of them quite large.

Here are the tools I used and the Plastex kit.

Repairing the fairings with Plastex is not a difficult process. I wanted to simply reinforce and repair the cracks from the back side while retaining the original finish on the outside of the fairings. To do this you simply need to:

Grind down the inside of the cracks with an air grinder or Dremel or similar tool.

Tape the broken pieces and/or the outer surface of the crack with packing tape

Pour Plastex powder into the groove you created and then add the liquid

Wait for it to dry and remove the tape.

Step 1

Here are some images of how I ground down the cracked fairing. I wanted to remove as much material from the back side of the break as I could without grinding through on the finished side. The closer you can get to the finished side the stronger the repair will be; provided you fill it in properly with Plastex. For projects where the outside will be refinished I would grind that side as well.

I also ground a groove into any cracks that weren’t already broken apart so they could be repaired as well.

Step 2

Next I simply taped the broken pieces back together. The tape keeps the pieces inline (so make sure things are lined up properly) and it keeps the liquid from the two part Plastex fix from seeping through and hurting the paint. The liquid in the Plastex kit does seem to act as a mild stripper if it sits directly on paint for a long time. Note that you may wish to reinforce some pieces that need to hold a certain shape as I did with the popsicle stick.

Step 3

I didn’t have anyone around to take pictures of this step so I don’t have an image for this step but it’s really quite simple. The Plastex kit consists of a bottle of powder and a bottle of liquid. Lay the piece to be repaired down so the crack faces straight up. Carefully dab a little powder into the crack left from step one. Then use the applicator bottle to put drops of the liquid on to the powder. The drips will level out the powder a bit. You can add as much fluid as needed; there really isn’t a ratio. Leave the part flat for around 20 minutes until it hardens and you can move on to another crack. Plastex doesn’t fully harden in 20 minutes but small fixes with thin applications such as this one are pretty solid after 20 minutes. Thicker applications need to dry longer and all applications should be left to dry for at least a couple hours before use.

Step 4

Once Plastex has been applied to all of the pieces and has dried thoroughly you can remove the tape. Plastex can be sanded and painted. For my purposes I was finished; since the repairs were inside the fairing where they weren’t readily visible I didn’t plan to finish them in any way. These repairs are quite solid and leave the bike in much better shape that when it arrived.

Conclusion

I’ve used Plastex for another motorcycle project as well as plastic repairs around the house and have found it very useful and quite strong! This was a very basic repair but in the past I have made replacement tabs and rebuilt missing pieces on motorcycle fairings with great results. I hope you found this helpful and feel free to comment if you have any feedback!